numerical modelling of surface and subsurface flow interactions in ...

NUMERICAL MODELLING OF SURFACE AND SUBSURFACE FLOW INTERACTIONS IN PAYA INDAH WETLAND OF SELANGOR D. E., MALAYSIA

BAHAA-ELDIN ELWALI ABDEL RAHIM ELWALI

THESIS SUBMITTED IN FULFILMENT OF THE REQUIREMENT FOR THE DEGREE OF DOCTOR OF PHILOSOPHY OF SCIENCE (PH. D.)

FACULTY OF SCIENCE UNIVERSITY OF MALAYA KUALA LUMPUR 2009

ii

PEMODELAN NUMERIKAL INTERAKSI ALIRAN PERMUKAAN DAN SUBPERMUKAAN DI TANAH LEMBAB PAYA INDAH, SELANGOR DE, MALAYSIA

BAHAA-ELDIN ELWALI ABDEL RAHIM ELWALI

TESIS YANG DIKEMUKAKAN UNTUK MEMPEROLEH IJAZAH DOKTOR FASAFAH SAINS

FAKULTI SAINS UNIVERSITI MALAYA KUALA LUMPUR 2009

iii

PREFACE

This thesis was prepared as one of the requirements for the Ph.D. Degree as well as a contribution to the formulation of the Paya Indah Water Resources Management Plan. The study has been carried out from March 2006 to December 2008. The Paya Indah Wetland Sanctuary with its ex-mining ponds at the southern portion and peat swamp forest at the northern portion may act as natural flood detention storage and therefore it is essential to understand the complex water balance of this wetland. The research focused on the mathematical modelling approach to model the hydrology and the water balance of the Paya Indah wetland and the surrounding peat swamp forest. The mathematical model is based on the integrated hydrological modeling system, MIKE SHE. This modeling system is particularly suited for wetland modeling because of its integration nature and the ability to count for both surface and subsurface flows and their interactions. Current and future researches will undoubtedly improve understanding of the basic concepts involved in this modelling project and may lead to more sophisticated flow and/or transport modelling(s). The modelling protocol and related procedures in this thesis are therefore validated and aimed to be used as a management tool, thus the model subject to continuous refinement as new data become available and new questions arise. This Ph.D. thesis contributes to the literature via participation in different national and international conferences; and publication in a few journals. Selective papers may include:

Bahaa-eldin E. A. R., Yusoff I., Azmi M. J, and Zainuddin O. 2009. Numerical modelling of tropical wetland catchment using MIKE SHE system: Calibration and Validation. Water Resources Research. Submitted

Bahaa-eldin E. A. R., Yusoff I., Azmi M. J, and Zainuddin O. 2009. Application of MIKE SHE modelling system to set up a water balance for Paya Indah wetland. Journal of hydrology. Submitted

Bahaa-eldin E. A. R., Yusoff I., Azmi M. J, and Zainuddin O. 2009. Predictions of hydrological modification on Paya Indah Wetland in Malaysia. Water Resources Management. Submitted.

iv Bahaa-eldin E. A. R., Yusoff I., Azmi M. J, and Zainuddin O. 2009. Simulation of integrated surface-water/groundwater flow for a freshwater wetland in Selangor State, Malaysia. Geological Society of Malaysia, Bulletin 55: 95 – 100.

Bahaa-eldin E. A. R., Yusoff I., Azmi M. J, and Zainuddin O. 2007. MIKE SHE modelling of surface water and groundwater interaction. National Geoscience Conference. Kota Kinabalu, Sabah; Malaysia. 7-9 June. P5A-4.

Bahaa-eldin E. A.Rahim, Yusoff, I., Azmi M.J. and Zainudin O. 2006. Modelling of hydrological interactions at Paya Indah Wetland, Malaysia. Proceedings of the 2nd Mathematics and Physical Science Graduate Conference. Faculty of Science, Building, National University of Singapore. Singapore, 12 – 14 December.

v ACKNOWLEDGEMENTS

The production of this thesis was made possible by the complementary funding from two different bodies including the Malaysian Ministry of Sciences, Technology & Environment under IRPA grant No. 02-03-08-003-EA003 and the University of Malaya under the Fellowship Scheme. Thanks are extended to the Department of Geology, Faculty of Science, and University of Malaya for all the provided facilities and assistance. My sincerest thanks are due to my Advisor Assoc. Prof. Dr. Ismail Yusoff for his constant guidance and encouragement throughout the study period. The author duly appreciates the cooperation and support of Hj. Mr. Azmi M. Jaffri the Head of Department of Drainage and Irrigation Department (DID) of Malaysia; Dr. Zainudin Othman from the Malaysian Nuclear Agency. Special gratefulness and appreciation are due to the helpfulness and gentleness of Mr. Salim from Drainage and Irrigation Department of Malaysia; Mr. Yagambaram V. (Baram) from Minerals and Geoscience Department of Malaysia/Selangor State Office; and Mr Ahamed Zaki from Malaysia Meteorological Department. I am also thankful Brother Mohammed who kindly and generously rescued the flow of work of this research project (Appendix K; Photo K.8). I am so grateful for Ir. Miss Azizah Abdul Gadir and Ir. Mrs. Atikah Shafae from Drainage and Irrigation Department of Malaysia for their special treatment. A sincere gratitude is extended also to all the staff of Department of Geology of University of Malaya, Drainage and Irrigation Department of Malaysia and Minerals and Geoscience Department of Malaysia. My final and special gratefulness and appreciation are due to my parents, sisters and brothers for their putting up with me and being patient all this while.

vi vi

vii ABSTRACT

MIKE SHE modelling system was used to simulate the surface and subsurface flow interactions at the Paya Indah wetland catchment which covers an area of 242.21 km2 and lies in Selangor State in west of Malaysian peninsular. The watershed hydrology has been changed considerably due to the increased anthropogenic activities, producing different hydro-ecological problems for the catchment. These include frequent peat forest fires and dropping of the surface water level in the Paya Indah lakes system. Being physically-based distributed hydrologic model, the MIKE SHE model set-up, therefore, requires a vast set of input data which precisely include rainfall, evapotranspiration, river cross-section, detailed soil hydraulic properties and aquifer characteristics. The model was calibrated and validated against three targets including surface water, channel flow and groundwater head. The multi-criteria evaluation and hydrographs visual judgments revealed that the model performance was satisfactory which allowed running the water balance and assessing the impact of the predicted future scenarios. Results revealed that elevated rate of the evapotranspiration losses and the landuse change impacts considerably influence the water level in the Paya Indah lakes system at rechargeable area of peat cover. On contrast during both calibration and validation periods it was found that groundwater abstraction controlled the dynamics of the groundwater within a large zone covered most of the downstream area of the catchment. The impact of over-abstraction at the Megasteel Co. Ltd. property on surface water level of the Paya Indah lakes system was investigated. It was found that the exchangeable flow between unsaturated zone and saturated is very limited at the area of the lakes system due to occurrence of impermeable clay layer of 10 m – 15 m thick and of a low permeability of an average value of 4.8E-7 m/s which acts as barrier that controls exchangeable flow between the unsaturated and saturated zones at this part of the catchment. Nonetheless, it was found that the current rate of pumping had influenced the groundwater table to drop as low as ∼ 4.0 m below sea level within the influenced zone of the Megasteel pumping wells which in turn, may rise up the potentiality of seawater intrusion and deep aquifer collapse. Looking at the overall water balance it is clear that evapotranspiration accounted for the largest water loss of ∼ 60 % of the total rainfall. The model was slightly underestimated the total water balances by 0.45 % and 0.21 % the total rainfall for the calibration and validation periods respectively. Hydrological scenarios that likely might alter the quantity and timing of water exiting the Paya Indah wetland catchment were simulated with the validated model (baseline scenario) in order to evaluate their impacts on the watershed’s hydrology. In this context, decreasing of the North-InletCanal (SWL1) inflow as a result of launching the flood mitigation new channel that diverts Cyberjaya water towards Klang River Basin is one of the expected impacts of the full development of the adjacent Cyberjaya City and E-village. While as the results revealed that the deep aquifer might deplete partially or totally depending on the quantity of the groundwater withdrawal.

viii PEMODELAN NUMERIKAL INTERAKSI ALIRAN PERMUKAAN DAN SUBPERMUKAAN DI TANAH LEMBAB PAYA INDAH, SELANGOR D.E., MALAYSIA ABSTRAK

Sistem pemodelan MIKE SHE telah digunakan untuk mengsimulasi interaksi aliran air permukaan dan sub-permukaan di lembangan tanah lembab Paya Indah yang merangkumi kawasan seluas 242.21 km2 yang terletak di Negeri Selangor, di barat Semenanjung Malaysia. Hidrologi lembangan ini telah berubah secara ketara akibat peningkatan aktiviti antropogenik yang menyumbang kepada masalah hidro-ekologi lembangan. Ini termasuklah kekerapan kebakaran hutan paya bakau dan kejatuhan paras air di sistem tasiktasik Paya Indah. MIKE SHE merupakan model hidrologi dasaran fizikal yang memerlukan pemasukan data yang banyak yang diantaranya termasuklah data kerpasan, evapotranspirasi, keratan rentas sungai, sifat hidraulik tanih dan ciri-ciri akuifer. Model ini telah dikalibrasi dan divalidasi dengan tiga sasaran kalibrasi termasuklah aras air permukaan, saliran dan air tanah. Penilaian yang dibuat menggunakan multi-kriteria dan pengvisualan hidrograf menunjukkan kebolehan model ini adalah memuaskan dan membolehkan kajian keseimbangan air dan kesan senario masa depan diramalkan. Hasil kajian ini menunjukkan peningkatan kadar kehilangan air secara evapotranspirasi dan perubahan guna tanah memberi perubahan ketara kepada aras air di dalam sistem tasik Paya Indah di kawasan imbuhan yang ditutupi oleh tanah gambut. Secara perbandingannya pula, sepanjang tempoh masa kalibrasi dan validasi adalah didapati pengambilan air tanah yang mengawal dinamik air tanah di dalam zon luas yang merangkumi sebahagian besar kawasan hilir lembangan. Kesan pengambilan air tanah secara ketara oleh Syarikat MegaSteel Sdn. Bhd kepada aras air di tasik-tasik Paya Indah juga dikaji. Adalah didapati aliran yang bertukarganti di antara zon tak tepu dan zon tepu amat terhad bagi kawasan tasik dimana terdapatnya lapisan lempung tak telap yang berketebalan antara 10 m-15 m dengan kadar ketelapan yang rendah dengan nilai puratanya adalah 4.8E-7 m/s yang juga bertindak sebagai penghalang kepada aliran tukarganti di antara zon tak tepu dan zon tepu di sebahagian lembangan ini. Apapun adalah didapati kadar pengepaman air tanah pada masa ini telah menyebabkan aras air tanah jatuh sedalam 4.0 m di bawah paras laut bagi kawasan yang dipengaruhi oleh telaga pengepaman Megasteel yang berpotensi besar menjadi penyebab kepada intrusi air laut dan kegagalan akuifer dalam. Berdasarkan keseimbangan air secara keseluruhan adalah jelas didapati evapotranspirasi menjadi penyumbang besar kepada kehilangan air lembangan sehingga mencapai 60 % dari keseluruhan kerpasan. Model ini memberi kurangan anggaran keseimbangan air semasa proses kalibrasi dan validasi masing-masing sebanyak 0.45% dan 0.21 % dari jumlah hujan keseluruhan. Model yang telah divalidasi digunakan untuk melihat senario hidrologi yang bakal mengubah kuantiti dan masa kedapatan air di lembagan tanah lembab Paya Indah bagi menilai kesan perubahan kepada tindakbalas hidrologi lembangan. Bagi kontek ini, pembangunan sepenuhnya kawasan Bandar Cyberjaya dan E-Village yang bersebelahan dengan model lembangan akan meyebabkan terbentuknya saliran pemulihan baru yang mengalihkan aliran air dari Cyberjaya ke lembagan Sg. Klang dan menghilangkan kemasukan air dari saluran North-Inlet (SWL1). Disamping itu, keputusan pemodelan menunjukkan akuifer dalam mungkin mengalami kejatuhan secara separa atau keseluruhan bergantung kepada kuantiti pengeluaran air tanah.

ix

CONTENTS Page PREFACE

iii

ACKNOWLEDGEMENTS

v

DECLARATION

vi

ABSTRACT

vii

ABSTRAK

viii

CONTENTS

ix

LIST OF FIGURES

xiv

LIST OF TABLES

xxi

LIST OF PHOTOGRAPHS

xxiii

LIST OF SYMBOLS AND ABBREVIATIONS

xxv

CHAPTER I

INTRODUCTION

1.1

Description of the Study Area

1

1.1.1 Geology 1.1.2 Hydrology 1.1.3 Groundwater status

3 5 8

1.2

Objectives

9

1.3

Scope of the Study

10

1.4

Importance of the Study

10

1.5

Modeling Approach

11

x CHAPTER II

LITERATURE REVIEW

2.1

Hydrologic Cycle

13

2.2

Watershed Hydrology

14

2.3

Water Resources Management Problems

17

2.3.1 Water resources problems in Malaysia

18

2.4

Soil Hydraulic Parameters

23

2.5

Ramsar Convention on Wetlands

25

2.5.1 Ramsar listed wetlands of Malaysia

26

Modelling

27

2.6.1 Watershed models

30

2.6

CHAPTER III

MODELLING TOOL

3.1

Hydrological Description

46

3.2

Hydrological Description

47

3.2.1 Interception and evapotranspiration components 3.2.2 Overland and channel flow component 3.2.3 Unsaturated zone components 3.2.4 Saturated zone components

49 53 56 58

CHAPTER IV

MODEL INPUT DATA

4.1

Hydro-meteorological Data

63

4.1.1 Rainfall 3.1.3 Evapotranspiration

63 66

4.2

Landuse and Vegetation

67

4.3

Surface Topography

69

4.4

Overland Flow and River Network

72

4.4.1 Overland flow 4.4.2 Flooded area

73 74

xi

4.5

4.6

4.4.3 Cross sections and bathymetry data

75

Unsaturated Zone

77

4.5.1 4.5.2 4.5.3 4.5.4 4.5.5

77 78 81 84 89

Types of soils Soil water Soil sampling and insitu measurements Soil characterization Presentation of soil tests results

Saturated Zone

91

4.6.1 Geological model 4.6.2 Aquifers characteristics 4.6.3 Interactions between the surface and subsurface flow 4.6.4 Groundwater abstraction

91 95 96

4.7

Surface water and Groundwater Timeseries Data

98

4.8

Model Set-up

98

4.8.1 Boundary conditions 4.8.2 Surface water flow system

99 103

4.9

Conceptual Model

105

4.10

Model Domain and Discretization

108

4.11

Model Development

110

4.11.1 4.11.2 4.11.3 4.11.4

111 112 112 112

Simulation time step Model Calibration Model Validation Model Performance

96

CHAPTER V

MODEL CALIBRATION AND VALIDATION

5.1

Calibration

117

5.1.1 Calibration targets 5.1.2 Primary calibration parameters

118 119

Calibration Results

120

5.2.1 Simulation of surface water level 5.2.2 Simulated groundwater heads

120 127

5.2

xii

5.3

5.4

5.5

5.6

5.2.3 Simulation of channel flow

132

Assessment of Calibrated Model

135

5.3.1 Performance of the coupled model 5.3.2 Assessment of model predictive capability

136 141

Validation

144

5.4.1 Validated surface water flow 5.4.2 Validated groundwater head 5.4.3 Validation of channel flow

145 150 151

Assessment of the Validated Model Performance

155

5.5.1 Performance of the coupled model 5.5.2 Assessment of model predictive capability

155 157

Sensitivity Analysis

159

5.6.1 Effect of increment of evapotranspiration rate 5.6.2 Effect of depletion of the inflow

162 165

CHAPTER V1

MODEL OUTPUTS

6.1

Water Balance

170

6.2

Saturated and Unsaturated Flow Interactions

176

6.2.1 Overland flow 6.2.2 Flow exchange between unsaturated and saturated zones 6.2.3 Saturated zone and river lateral flow

176 177

6.3

Hydrological Impact of Groundwater Abstraction

181

CHAPTER V1I

SCENARIOS

7.1

Cyberjaya Development Flagship Zone: Phase II

186

7.2

Cyberjaya Full Development and the E-village

188

7.3

Replacement of Peat Layer

191

7.4

Groundwater over- abstraction

194

180

xiii CHAPTER V1II

SUMMARY AND CONCLUSIONS

8.1

Summary

196

8.2

Conclusions

197

CHAPTER IX

RECOMMENDATIONS

9.1

challenging Issues

201

9.2

Recommendations

202

REFERENCES

204

APPENDICES A

Criteria for the Designation of Wetlands of International Importance

220

B

Ramsar-nominated Wetlands of Malaysia

221

C

Polynomial Approximation of IDF Curves

226

D

Monthly Rainall atthe Paya Indah Wetland Catchment

232

E

Monthly Evapotranspiration at the Paya Indah Wetland Catchment

233

F

River-cross Section Data

234

G

Malaysian Soil Series

237

H

Soil Profile Definition and Soil Parameters used in the Model

238

I

Engineering Borehole Log for PI 1

241

J

Pumping Test Data

244

K

Album

254

xiv LIST OF FIGURES Figure No.

Page

1.1

Index map of the Study Area

2

1.2

Geological and Location Map of the Study Area

4

1.3

Components of the Paya Indah Lakes System

6

1.4

Land Phase Components of the Hydrologic Cylce

12

2.1

A System Representation of the Hydrologic Cycle

14

2.2

Hydrologic cylce components with golobal annual average water balance given in units relative to value of 100 for the precitiparion rate on land

15

2.3

Classification of hydrologic models

28

2.4

The modelling protocol and schedule proposed for the present study

29

3.1

Schematic Representation of MIKE SHE Model

48

3.2

Schematic Diagram of Interception and Evapotranspiration

49

4.1

Estimated Rainfall Fields for the Catchment using Thiessen-polygon Method

64

4.2

Hyetograph of the Paya Indah Wetland Catchment 65

4.3

Daily Evapotranspiration for the Paya Indah Wetland Catchment

66

4.4

Landuse Map of the Paya Indah Wetland Catchment

67

4.5

Topography Data

70

4.6

Layout of Paya Indah Lakes System showing the Locations of the Spot Level Data

71

4.7

Topographic Model of the Paya Indah Wetland Catchment

71

4.8

Zooming-in for Set-up of Channel Flow Network the Location of Hydrodynamic Boundaries, Cross-sections, Culvert and the Lotus Lake Outlet Controlled Gate

72

xv 4.9

Flooded Areas within of the Paya Indah Wetland Catchment: Lakes names and their representing code number

74

4.10

Bathymetry model

75

4.11

Longitudinal Profile for Tin Lake, Tin-Perch-Connect and Perch Lake

76

4.12

Longitudinal Profile for Tin Lake, Tin-Perch-Connect and Chalet Lake

77

4.13

Soil Map of the Paya Indah Wetland Catchment

78

4.14

Overview of Soil Volume/Weight Relationship: “V” and “W” represent volume and weight, respectively; “soil” refers to the fine earth fraction (any combination of sand, silt and clay minerals mixed with soil organic matter and pores), but excludes coarse fragments (CF); “soil particles” refer to fine earth minerals and organic matter. Solid refers to fine earth +CF. Total volume refers to fine earth, CF and pores.

79

4.15

Locations of Soil Sampling and Insitu Measurements

82

4.16

Infiltration Test for the Selangor-Kanchung Series. Location: Kg Sg Manggis (Mangostine River Village)

88

4.17

Presentation of a Geological Cross-section across the Modelled Area

91

4.18

Thickness of the Geological Layer 1

93

4.19

Thickness of the Geological Layer 2

94

4.20

Thickness of the Geological Layer 3

94

4.21

Location of Monitoring and Production Wells within the Modelled Area

97

4.22

Boundary Conditions for the Study Area

100

4.23

Conceptual Model of the Paya Indah Wetland Catchment

107

4.24

Model Domain and Grid

109

4.25

Mesh Discretization for the Study Area

110

xvi 5.1

Calibrated Water Level Hydrograph for North-Inlet-Canal (SWL1) 121

5.2

Calibrated Water Level Hydrograph for Visitor Lake

122

5.3

Calibrated Water Level Hydrograph for Main Lake

122

5.4

Calibrated Water Level Hydrograph for Driftwood Lake

123

5.5

Calibrated Water Level Hydrograph for Perch Lake

123

5.6

Calibrated Water Level Hydrograph for Marsh Lake

124

5.7

Calibrated Water Level Hydrograph for Crocodile Lake

124

5.8

Calibrated Water Level Hydrograph for Hippo Lake

125

5.9

Calibrated Water Level Hydrograph for Chalet Lake

125

5.10

Calibrated Water Level Hydrograph for Typha Lake

126

5.11

Calibrated Water Level Hydrograph for Lotus Lake

126

5.12

Calibrated Water Level Hydrograph for Lotus-Outlet (SWL2)

127

5.13

Calibrated Groundwater Head Hydrograph for BH1

128

5.14

Calibrated Groundwater Head Hydrograph for BH2

129

5.15

Calibrated Groundwater Head Hydrograph for BH3

129

5.16

Calibrated Groundwater Head Hydrograph for BH4

130

5.17

Calibrated Groundwater Head Hydrograph for BH5

130

5.18

Calibrated Groundwater Head Hydrograph for BH6

131

5.19

Calibrated Groundwater Head Hydrograph for BH7

131

5.20

Calibrated Groundwater Head Hydrograph for BH8

132

5.21

Calibrated Channel Flow Hydrograph for SWL1

133

5.22

Hyetograph and Hydrographs for SWL1

133

5.23

Calibrated Channel Flow Hydrograph for SWL2

134

5.24

Hyetograph and Hydrographs for SWL2

135

xvii 5.25

Scattered Plot for the Observed and Simulated Channel Flow at SWL1 during Calibration Period

142

5.26

Scattered Plot for the Observed and Simulated Channel Flow at SWL1 during Calibration Period

143

5.27

Validated Water Level Hydrograph at Visitor Lake

146

5.28

Validated Water Level Hydrograph at Main Lake

146

5.29

Validated Water Level Hydrograph at Tin Lake

147

5.30

Validated Water Level Hydrograph at Crocodile Lake

147

5.31

Validated Water Level Hydrograph at Hippo Lake

148

5.32

Validated Water Level Hydrograph at Chalet Lake

148

5.33

Validated Water Level Hydrograph at Typha Lake

149

5.34

Validated Water Level Hydrograph at Lotus Lake

149

5.35

Validated Groundwater Head Hydrograph at BH3

150

5.36

Validated Groundwater Head Hydrograph at BH5

151

5.37

Validated Channel Flow Hydrograph for the Reach of Langat River

152

5.38

Validated Channel Flow Hydrograph for SWL2

153

5.39

Hyetograph and Validation Hydrographs for Reach of the Langat River

154

5.40

Hyetograph and Validation Hydrographs for SWL2

154

5.41

Scattered Plot for the Observed and Simulated Channel Flow at the Reach of Langat River during Validation Period

158

5.42

Scattered Plot for the Observed and Simulated Channel Flow at SWL1 during validation Period

158

5.43

Sensitivity Run for Assessing the Effect of ET Increment on Surface water Level at SWL1

163

5.44

Sensitivity Run for Assessing the Effect of ET Increment on Surface water Level at Typha Lake

163

xviii 5.45

Sensitivity Run for Assessing the Effect of ET Increment on Surface water Level at BH3

164

5.46

Sensitivity Run for Assessing the Effect of ET Increment on Surface water Level at BH5

164

5.47

Sensitivity Run for Assessing the Effect of Flow Depletion at Visitor Lake

166

5.48

Sensitivity Run for Assessing the Effect of Flow Depletion at Main Lake

167

5.49

Sensitivity Run for Assessing the Effect of Flow Depletion at Crocodile Lake

167

5.50

Sensitivity Run for Assessing the Effect of Flow Depletion at Chalet Lake

168

5.51

Sensitivity Run for Assessing the Effect of Flow Depletion at Lotus Lake

168

5.52

Sensitivity Run for Assessing the Effect of Flow Depletion at SWL2

169

6.1

Water Balance for Paya Indah Wetland Catchment (∼ 242 km2) for the Simulation Period 1/July/1999 to 31/October/2004

171

6.2

Water Balance for Paya Indah Wetland Catchment (∼ 242 km2) for the Simulation Period 1/August/2007 to 2/August/2008

172

6.3

Distribution of Actual evapotranspiration at Paya Indah Wetland Catchment during a Normal Day in the Wet Season

174

6.4

Distribution of Actual evapotranspiration at Paya Indah Wetland Catchment during a Normal Day in the Dry Season

175

6.5

Depth of Overland Water during a Normal Day in Wet season

177

6.6

Unsaturated-Saturated Zones Flow Exchange during a Normal Day during Wet Season.

178

6.7

Unsaturated-Saturated Zones Flow Exchange during a Normal Day during Dry Season.

179

6.8

Flow Exchange between Saturated Zone and Channel Flow 180

6.9

Impact of Groundwater Pumping at the Megasteel Wells on the Groundwater Head Elevation

182

xix 6.10

Impact of Groundwater Pumping at the Megasteel on Groundwater Flow Direction

183

7.1

Layout of Baseline Scenario

186

7.2

Layout of Phase II of Cyberjaya Development Scenario

187

7.3

Impact of Phase II Development of Cyberjaya on the Groundwater Table in the Peat Layer

188

7.4

Effect of Depletion of the Inflow from Cyberjaya on Main Lake

189

7.5

Effect of Depletion of the Inflow from Cyberjaya on Crocodile Lake

189

7.6

Effect of Depletion of the Inflow from Cyberjaya on Chalet Lake 190

7.7

Effect of Depletion of the Inflow from Cyberjaya on Lotus Lake

190

7.8

Impact of Full Development of Cyberjaya and E-village on the Groundwater Table in the Peat Layer

191

7.9

Layout of the Peat Basin

192

7.10

Effect of Replacement of the Peat Layer by a Low Permeability Soil Material on Tin Lake

193

7.11

Effect of Replacement of the Peat Layer by a Low Permeability Soil Material on BH3

193

7.12

Effect of Replacement of the Peat Layer by a Low Permeability Soil Material on BH5

194

C.1

Rainfall Intensity-duration-frequency (IDF) Curve for the Paya Indah Wetland Catchment of the Pumping Test

227

C.2

Frequency of Storm Events in 2-years Period

228

C.3

Frequency of Storm Events in 5-years Period

228

C.4

Frequency of Storm Events in 10-years Period

229

C.5

Frequency of Storm Events in 25-years Period

229

C.6

Frequency of Storm Events in 50-years Period

230

C.7

Frequency of Storm Events in 25-years Period

230

xx J.1

Location of the Pumping Test

244

J.2

Result of constant rate pumping test at Observation well PI1

246

J.3

Result of constant discharge pumping test at Observation well PI1 248

xxi LIST OF TABLES Table No.

Page

1.1

Names and lengths of the Hydrologic System Components of the Paya Indah Wetland Catchment Model

7

2.1

Water Resources in Malaysia

19

4.1

Rainfall Area Weighted Factors for the Paya Indah Wetland Catchment

64

4.2

Properties of Vegetation within the Paya Indah Wetland Catchment

68

4.3

Soil Hydraulic Properties used in for the Model

89

4.4

Characteristics of Shallow and Deep Aquifers at the Paya Indah Wetland Catchment

95

4.5

Roughness Coefficient (Manning’s coefficient) used for the Channels in the study area

104

5.1

Statistical Evaluation Criteria for the Calibrated Model

139

5.2

Evaluation of the Predictive Accuracy of the Calibrated Model

141

5.3

Statistical Evaluation Criteria for the Validated Model

156

5.4

Evaluation of the Predictive Accuracy of the Validated Model

157

5.5

Model Parameters and Statistical Evaluation of Each Calibration and Validation Simulation Run

160

5.6

Sensitivity of Different Flow Rate Modifications at SWL1

166

6.1

Water Balance Estimation at the Paya Indah Wetland Catchment: Contribution of each Component

173

7.1

Impacts of Groundwater Over-abstraction Scenarios

195

A.1

Criteria for the Designation of Wetland of International Importance

220

C.1

Coefficients of the Fitted IDF Equation for Kuala Lumpur

227

C.2

Rainfall Intensity-duration-frequency (IDF) Estimation for the

231

xxii Paya Indah Wetland Catchment D.1

Monthly Rainfall at for the Paya Indah Wetland Catchment

232

E.1

Monthly Evapotranspiration at for the Paya Indah Wetland Catchment

233

F.1

Dimensions and Basic Statistics for the Cross sections of the River Network for the Modelled catchment

234

G.1

Malaysian Soil Series

237

H.1

Soil Profile Definition and Soil Parameters used in the Model

238

I.1

Engineering Borehole Log for PI1

241

J.1

Data of Constant Rate Pumping Test a the Observation Well PI1

245

J.2

Data of the Recovery Test a the Observation Well PI1

247

J.3

Determination of Hydraulic Conductivity for the Deep Aquifer Using Constant Head Permeability Test at Borehole PI1

249

J.4

Determination of Hydraulic Conductivity for the Second Layer Using Constant Head Permeability Test at Borehole PI2

250

J.5

Determination of Hydraulic Conductivity for the Shallow Aquifer 251 Using Constant Head Permeability Test at Borehole PI3

J.6

Measurements of Ground Subsidence at Megasteel Co. Ltd Area for the period 2001 – 2006

252

J.7

Measurements of Ground Subsidence at Megasteel Co. Ltd Area for the period 2000 – 2007

253

xxiii LIST OF PHOTOGRAPHS PHOTO No.

Page

K.1

Kick-start Visit1

254

K.2

Kick-start Visi2

255

K.3

Peat Big Days

256

K.4

Infiltration Test at Kg Sg Manggis

257

K.5

Infiltration Test near the marsh Lake

258

K.6

Retrieving Groundwater Data of BH3

259

K.7

Checking the Coordinates of BH6 before Retrieving the Groundwater Level Data from the Automatic Logger.

260

K.8

Heading towards BH6 across the Langat River

260

K.9

Gauging at SWL1

261

K.10

Gauging at SWL2

262

K.11

Automatic logger at SWL1

263

K.12

Automatic logger at SWL2

264

K.13

Automatic logger at Main-Visitor Connection

264

K.14

Inflow from Cyberjaya City on a Rainy Day. The North South Expressway Central Link (NSECL) also appears on the picture

265

K.15

Visitor Lake Overview

266

K.16

Main Lake Overview

266

K.17

Culvert of the Main-Palm Connection

267

K.18

Main-Palm Connection heading towards the Lotus Lake

267

K.19

Overview of the Main and Driftwood Lakes

268

K.20

Tin-Driftwood Connection

268

K.21

Padi (ex-) Lake and it Functionless Culvert

269

xxiv K.22

Swamp-hen (semi-) Lake Overview

270

K.23

Connection Point between Lotus-Swamp-hen Connection and Lotus Lake

271

K.24

Typha Lake Overview

272

K.25

Lotus lake Overview

272

K.26

Lotus-outlet Control Gate: Front View

273

K.27

Lotus-outlet Control Gate: Front View

273

K.28

Outlet heading towards Langat River

274

K.29

Wildlife Habitats

274

K.30

Deep inside the Peat Paradise’s Blanket

275

xxv LIST OF SYMBOLS AND ABBREVIATIONS

b.s.l.:

below the sea level

BH:

Borehole

CE:

Coefficient of efficiency

DID:

Drainage and Irrigation Department of Malaysia

ET:

Actual Evapotranspiration

Evap:

Evaporation

Exfilt:

Exfiltration

GIS:

Geographic information system

Infilt:

Infiltration

k:

Hydraulic conductivity

Kg:

Kampung (village)

KLIA:

Kuala Lumpur International Airport

m:

Meter

M:

The reciprocal of Manning’s n

MAE:

Mean average error

ME:

Mean error

MLD:

Mined Land

MMD:

Malaysia Meteorological Department

n:

Manning’s number

NSECL:

North-South Expressway Central Link

OL:

Overland flow

P:

Probability

P:

Precipitation

xxvi PRG:

Perang soil series

QG,in:

Groundwater flow into the model area

QG,out:

Groundwater flow out of the model area

QS:

Surface water inflow

QS,out:

Surface water flow out of the model area

R:

hydraulic radius

R:

Coefficient of correlation

R2 :

Pearson type-I distribution index

RMSE:

Root mean square error

Sc:

Storage coefficient of groundwater

S:

channel bed slope

SBM.

Serdang-Bungor-Munchong soil series

Sg:

Sungai (River)

SKG:

Selangor-Kanchung soil series

STDres:

Standard deviation of the residuals

SZ:

Saturated zone

UZ:

Unsaturated zone

T:

Transmissivity

Trans:

Transpiration

V:

Flow velocity

∆S:

Change in storage of surface water, unsaturated zone and groundwater (Ss+(Suz+(S sz)

xxvii